It normally involves dipping the item into a bath of hot caustic soda. I've had some doors stripped this way, very effective. It won't work by painting it on.
Make sure you add the caustic soda to water, and not vice-versa. It generates an awful lot of heat - also be careful which type of wood you dip - the mixture will turn some woods black. Oak in particular, not sure which others.
Caustic - usually Sodium Hydroxide or Potassium Hydroxide, is a base/alkaline substance which works in the same way you'd expect acid to. It's burns the skin and eyes like you wouldn't believe, so be very very careful. You should bring the furniture to a specialist - don't mess about at home.